Lifting apparatus

ABSTRACT

A container load lifting fork lift truck attachment having spaced hollow elements to receive said forks and through which passes a substantially horizontal frame element having double cantilever transverse arms at each end thereof with lockable container engaging devices at their end portions, power operable means being provided to cause relative movement between frame element and forks and between the fork receiving elements and the forks and for locking and unlocking the container engaging devices.

United States Patent [1 1 [111 3,709,392 Kinross [451 Jan. 9, 1973 [54] LIFTING APPARATUS [56] References Cited [75] Inventor: John Kinross, Aylesbury, England UNITED STATES PATENTS [73] Assignee: Lancer Boss Limited, Leighton Buz- 3,552,557 1/1971 Green ..2l4/620 zard, Bedfordshire, England b S Primary Examiner-R0 ert J. par [22] Flled' 1970 Attorney-Snyder and Butrum [211 App]. No.: 68,246

[57] ABSTRACT [30] Foreign Application Priority Data A container load lifting fork lift truck attachment having spaced hollow elements to receive said forks and p 1969 Great Britain 2/69 through which passes a substantially horizontal frame element having double cantilever transverse arms at [52] U.S.Cl. ..2l4/620,294/67 D A each end thereof with lockable container engaging [51] Int. Cl. ..B66f 9/14 devices at their end por i ns, power operable means [58] Field of Search.....2l4/620, 621, 730; 294/67 D, being provided to cause relative movement between 294 7 D A frame element and forks and between the fork receiving elements and the forks and for locking and unlocking thecontainer engaging devices.

7 Claims, 3 Drawing Figures PATENTEDJAN 9 I975 SHEET 2 OF 3 I nvenlor PATENTED JAN 9 I975 SHEET 3 OF 3 In venlor LIFTING APPARATUS BACKGROUND OF THE INVENTION Field of the Invention This invention relates to load lifting apparatus and more particularly to an improvement in or modification of a load lifting attachment for use with a fork lift truck for lifting loads from above.

The attachment of the present invention is particularly suitable for use in mechanically handling containers used in the modern method of containerization for transporting loads packed in box-like closed containers in which the goods can be transported without disturbance in land, sea or air vehicles and/or craft and may be mechanically moved from one transport vehicle to another. Such containers are now of standard length, width and height, and are generally rectangular in form with apertures in reinforced corner units at their four upper corners into which lifting means such as twist locks with downwardly projecting bayonet type locking elements can be engaged; the locks are mounted on the lifting means and rotated to lock them in the apertures or to unlock them by suitable means such as hydraulic rams on or operatively connected to the forks or members associated therewith.

The main object of the present invention is to provide an improved lifting attachment which is simple to manufacture and operate.

SUMMARY According to the present invention an improvement in or modification of a load lifting attachment comprises a unitary substantially horizontal frame element having secured thereto at each of its end portions a transverse double cantilever arm with a load engaging device at each end portion of each cantilever arm, a pair of fork receiving elements translatable longitudinally of the frame element and having fork receiving portions transversely of the frame element, a power operated device connected to each fork receiving element and connectable to the fork received thereby, and a power operated device connected between the frame element and at least one of the fork receiving elements for effecting relative movement between the elements.

Preferably the frame element comprises a'box girder construction or it comprises two I-beams with their flanges horizontal, the upper and/or lower flanges being secured together in juxtaposed relationship, as by welding.

The fork receiving elements preferably each comprise a box like unit having an upper transverse apertore through which the beam passes and a lower transverse aperture transversely of the beam through which the arm ofthe fork passes.

The fork receiving elements may carry on each side one or more freely journalled rollers disposed to ride on the upper surface of the forks when received in the elements.

Each fork receiving element may have rollers freely journalled therein disposed to roll along 'a horizontal surface or surfaces extending along the frame elements.

A hydraulic ram is preferably provided with its cylinder or piston connected to the frame element and its piston or cylinder respectively connected to one or both ofthe frame elements.

If desired the fork receiving elements may be interconnected so that they move as a unit on the main frame or frame element or they may be capable of being connected together with different but fixed distances between them so that the space between them can be adjusted to suit fork lift trucks where the forks are different distances apart. In this construction when they are adjusted to their spacing the fork lift elements may be secured together or secured to the main elements.

The cantilever arms at the ends of the frame elements may be variable in length and fixable at the selected length. For this purpose: they may be made telescopic for example.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more fully understood one construction in accordance therewith will now be described by way of example with reference to the accompanying drawings, in which:

FIG. I is a plan view of the load lifting attachment;

FIG. 2 is a side elevation of the attachment in FIG. 1; and,

FIG. 3 is an end elevation of the attachment in FIG. 1.

In the drawings the same references have been used to designate the same parts.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings the load lifting attachment to be described therewith is constructed for use with a fork lift truck for lifting loads from above by means of the forks of the truck (not shown in the drawings) which are in the conventional way carried on the carriage riding on the upwardly extensible masts of the fork lift truck. The truck itself forms no part of the present invention and needs no further description here.

In the drawings the attachment comprises a unitary substantially horizontal frame element indicated generally at 1 having secured thereto at each of its end portions 2,3 a transverse double cantilever arm 4. A pair of fork receiving elements 5 are mounted on the frame element 1 to be translatable longitudinally thereof, and are provided with fork receiving portions 6 disposed through the elements 5 transversely of the frame element 1.

The element 1 is of a rigid construction which is capable of withstanding the bending moments throughout its length to which it can be subjected in use, as well as the shear stress therein and any torque which might be applied thereto in use particularly if the container being lifted is out of balance in itsload. Altcrnatively, and as shown in the drawings, the beam is made of two horizontal'l-beams each disposed with its upper and lower flanges horizontally interconnected by the web which is vertical, the contiguous edges of the two flanges of the two beams being welded throughout their length as indicated at 7, the internal webs being indicated at 8.

The cantilever arms 4 are secured at the end 2 of the element 1 as by welding 9 and are formed of an I-beam disposed with its web horizontal and its flanges 11 vertical and having a bracing member 12 at each end between which there is a vertical reinforcing plate-like element 14 the whole being welded together. Also a plate 15 is welded to the cantilever arms and also to the element 1 to resist any twist of the cantilever arms with respect to the beam.

The ends of the arms may be fixed so that the attachment is used with a container of a particular standard size or they may be telescopically arranged with clamping means of conventional construction so that they can be varied in length to suit loads of different widths.

At the ends of the cantilever arms and in particular on the ends remote from the truck that is to say the lower ends in FIG. 1 stop members 16 may be mounted ,on the arms 4 to embrace the edges of the container while at the other ends of the cantilever arms, at the top of FIG. 1, the guide means can be rotated with respect to the arms so that they can be raised out of the path of the load beneath the attachment as it is being centered on the load.

Each end of the arms 4 has depending therefrom a locking device 17 which is actuated by an hydraulic cylinder 19.

The fork receiving elements 5 are in the form of open boxes so that they slide along the beam. They are provided with rollers 20 journalled in them which ride on the lower flange 21 of the element 1 thereby acting as rails for the movement of the rollers and permitting free movement of the rollers with respect to the element 1. Additional rollers 22 may also be provided on the elements 5 which roll on the underside of the flanges 21.

The fork receiving portions 6 are so disposed that when the forks are passed therethrough by the driver of the fork lift truck operating his controls, the forks will enter the recesses 6 beneath the element 1. The elements 5 are provided with rollers 23 shown as 3 on each side of the elements 5 but one or more may be used, which when the forks are in the recesses 6 will ride on the top of the surfaces of the forks thus facilitating movement of the forks with respect to the element 1 or vice versa.

Attached to each element 5 is a bracket 24 to which is pivoted the piston rod 25 of an hydraulic cylinder 26 the other end of which has an eye 27 through which a fixing pin (not shown) can be passed to enter one of a number of slots formed in the fork arms. Alternative brackets 24 are provided on the other side of each element 5 so that the pistons and cylinders 25,26 can be either side of the element 5.

The right hand element in FIG. 1 carries brackets 27 between which can be pivoted the piston rod 28 (FIG. 2) of a cylinder 29 the other end of which is pivoted at 30 to brackets 31 rigid with the upper face of the element l. Thus by operating the ram 28,29 from the controls of the fork lift truck by the driver thereof the right hand element 5 can be translated backwards and forwards along the element 1. A similar connection between the left hand element 5 and the left hand end of the element 1 may be provided if desired. Alternatively the two elements 5 can be interconnected by a rigid member so that they move in unison on operation of the ram 28,29. This rigid connection may if desired be such that the distance although fixed for any particular use, between the two elements 5 can be adjusted and then the elements locked in that position so that the attachment can be suitable for working with different fork trucks where the forks are different distances apart.

In operation it will be understood that when the attachment is mounted on the forks of the truck and the eyes 27 of the ram 25,26 are secured to the fork arms, operation of one or both of the cylinders 26 will enable the attachment to be moved longitudinally along the forks. If only one of those cylinders is operated then the angle between the element 1 and the fork can be adjusted within the given tolerance of the gap between the fork and the wall of the recesses 6 in the elements 5 which normally amounts to about 5 degrees either side of a dead center line.

Equally by operating the ram 28,29 the element 1 i can be translated along the elements 5 so that the load which is supported from the container can be brought into balance about the forkarms.

I claim:

1. A load lifting device for use with a fork lift truck for lifting containers from above, comprising in combination:

an elongate main frame having at least a portion of box-like cross section to resist bending and torsion;

a pair of fork receiving means for longitudinal movement along said main frame, each fork receiving means enclosing said box-like portion of the main frame and having opposite side portions closely adjacent opposite sides of said box-like portion of the main frame to react against torsional loading imparted to said main frame by a load, first bearing means on each fork-receiving means adjacent the opposite sides of said box-like portion of the frame and engaging bottom surfaces of said box-like portion of the main frame adjacent said opposite sides of the frame to support same and any load carried thereby, the opposite side portions of each fork receiving means defining fork receiving openings transverse to and below said main frame, and second bearing means on said opposite side portions and aligned below said bottom surfaces of said box-like portion of the main frame for engaging upper surfaces of forks in substantially the same plane as the engagement between said first bearing means and said frame to support the device from such forks;

a pair of transverse double cantilever arms, one fixed to each end of said main frame;

means at each end of each of said double cantilever arms for selectively engaging the corners of a container to be lifted;

power operated means connected between said main frame and at least one of said fork receiving means for moving same longitudinally of said main frame;

power operated means on at least one of said fork receiving means for shifting said device along the forks; and

wherein each of said fork receiving means comprises a box like unit having an upper transverse channel through which said main frame passes and lower longitudinal channel through which each associated fork passes.

2. A load lifting attachment according to claim 1, wherein said main frame comprises two l-beams with their flanges substantially horizontal, at least one of their contiguous upper and lower flange edges being secured together in juxtaposed relationship, e.g. by welding.

3. A load lifting attachment according to claim 1, wherein the last mentioned of said bearing means comprises at least one roller freely journalled on said fork receiving means and disposed to ride on the upper surface of said fork when received in said fork channel.

4. A load lifting attachment according to claim I, wherein the first of said bearing means comprises at least one roller freely journalled on each fork receiving 

1. A load lifting device for use with a fork lift truck for lifting containers from above, comprising in combination: an elongate main frame having at least a portion of box-like cross section to resist bending and torsion; a pair of fork receiving means for longitudinal movement along said main frame, each fork receiving means enclosing said boxlike portion of the main frame and having opposite side portions closely adjacent opposite sides of said box-like portion of the main frame to react against torsional loading imparted to said main frame by a load, first bearing means on each fork-receiving means adjacent the opposite sides of said box-like portion of the frame and engaging bottom surfaces of said box-like portion of the main frame adjacent said opposite sides of the frame to support same and any load carried thereby, the opposite side portIons of each fork receiving means defining fork receiving openings transverse to and below said main frame, and second bearing means on said opposite side portions and aligned below said bottom surfaces of said boxlike portion of the main frame for engaging upper surfaces of forks in substantially the same plane as the engagement between said first bearing means and said frame to support the device from such forks; a pair of transverse double cantilever arms, one fixed to each end of said main frame; means at each end of each of said double cantilever arms for selectively engaging the corners of a container to be lifted; power operated means connected between said main frame and at least one of said fork receiving means for moving same longitudinally of said main frame; power operated means on at least one of said fork receiving means for shifting said device along the forks; and wherein each of said fork receiving means comprises a box like unit having an upper transverse channel through which said main frame passes and lower longitudinal channel through which each associated fork passes.
 2. A load lifting attachment according to claim 1, wherein said main frame comprises two I-beams with their flanges substantially horizontal, at least one of their contiguous upper and lower flange edges being secured together in juxtaposed relationship, e.g. by welding.
 3. A load lifting attachment according to claim 1, wherein the last mentioned of said bearing means comprises at least one roller freely journalled on said fork receiving means and disposed to ride on the upper surface of said fork when received in said fork channel.
 4. A load lifting attachment according to claim 1, wherein the first of said bearing means comprises at least one roller freely journalled on each fork receiving means, and said main frame has a longitudinal substantially horizontal track along which said rollers roll.
 5. A load lifting attachment according to claim 1, wherein each said power operated means comprises an hydraulic ram.
 6. A load lifting attachment according to claim 1, wherein said fork receiving means are interconnected to move as a unit and means are provided to adjust the distance between them.
 7. A LOAD lifting attachment according to claim 1, wherein said cantilever arms are adjustable in length and means are provided to secure them at predetermined lengths. 